I have an Ecore model, where I'm trying to add some OCL constraints.
My problem comes when I try to make a property (a string) that is in valid IPv4 form. I guess I should use a regular expression, but I have no idea at all about how to use regex on OCLinEcore.
As of Eclipse Juno, you can use regular expressions in OCL. The function to call on it is matches(regex), just like in Java.
Source: http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.ocl.doc%2Fhelp%2FCompleteOCLTutorial.html
If you have a previous version of Eclipse, then I suggest adding a Java constraint on your Ecore element, then validate your element through the generated Java template code.